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vrsf 5 or 7 for a pure stage 2 turbo ?
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04-26-2017, 02:49 PM | #1 |
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vrsf 5 or 7 for a pure stage 2 turbo ?
hey guys i have a 335i x drive FBO on meth 90/10 but im still on stock intercooler
im buying a pure stage 2 really soon and id like to know if u should get a 5" intercooler or the 7" from vrsf i go to the dragstrip a couple times during the summer and i do a few pulls a day. i was thinking since i spray meth during my pulls i would only need a 5" but i heard the pure stage 2 needs more cooling ( not sure ) please be honest the ones who have the 7 do you notice a bit more lag ? id like your opinions and thoughts about this they are both at same price so its purely for choosing the best one for my needs |
04-26-2017, 02:56 PM | #2 | |
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04-26-2017, 02:56 PM | #3 |
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Personally, I think if you don't track the car the 5" will be fine. But I am pretty new on this platform so what do I know.
I am pretty sure they are both the same price if you buy them new, so if you don't mind trimming pieces off you car might as well go for the 7", but solely for that reason I am installing a 5". I am also probably not going PS2.
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Current: 2011 BMW 335xi | Wedge Tuned | Meth | VRSF DP | VRSF 5" Intercooler | VRSF Chargepipe | BMS Intake | xHP Stg 3
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04-26-2017, 03:00 PM | #4 |
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about 5 degrees when doing a few puils back to back its very negligible bout its still cold here ( montreal canada 7 celsius ) so i bet when summer comes it will rise more
i went to the drag strip and did 25 runs all on 20 psi meth i started at 10iat and after my 25 runs ( almost back to back track was empty ) my iat were at 140 and i left cause heat soaked so imo meth is doing a hell of a job to lower iat but well see with the real test ( summer ) |
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04-26-2017, 03:06 PM | #5 | |
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04-26-2017, 04:20 PM | #6 | |
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04-26-2017, 06:28 PM | #8 |
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04-26-2017, 09:38 PM | #9 | |
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04-26-2017, 10:24 PM | #10 |
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Oh nice. When did you install that? Last I knew you were still on the stock ic with meth.
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04-27-2017, 10:18 AM | #11 |
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Im FBO with VRSF 7"HD http://www.datazap.me/u/3dirty5/vrsf...=0&data=4-6-13
notice how the temps drop as i get on it . Theres around a .5-.75 psi drop in pressure when i switched from stock to vrsf |
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04-27-2017, 10:42 AM | #12 |
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HD is a higher quality, more efficient, denser core- AKA better IAT suppression and performance.
Last edited by Jeff@TopGearSolutions; 04-30-2017 at 02:39 PM.. |
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04-27-2017, 12:31 PM | #13 | |
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1 psi = 10whp so lets say you loose 8 whp but youll get same power on each pull since iat is lower am i right or no ? |
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04-27-2017, 05:27 PM | #15 |
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04-28-2017, 01:16 PM | #16 |
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Ken posted a log of his car with an ETS 5" and meth reducing IAT's across a pull...
Three posts below that and there is a vendor suggesting a 7" super duper HD ultra (Chinese crap) VRSF intercooler is the only way to go... Spraying water/meth changes everything. 7in HD might be "more efficient" because of its denser core, but the drawback of that is the additional weight penalty and the restriction to airflow. Everything with intercoolers is a tradeoff so more efficient does not always equate out to better performance. You'll see lower velocity airflow, a greater pressure drop across the intercooler, and greater spool time since you'll have to fill a larger volume. All of which is unnecessary seeing as how Meth + 5" is already more than enough to keep IAT's stable. No intercooler is going to help you after 25 pulls back to back. Your engine bay was probably north of 300f. Seems like your current setup is already decent if you only see a 5f increase across a 4th gear pull. Last edited by bbnks2; 04-28-2017 at 01:26 PM.. |
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04-28-2017, 01:26 PM | #17 |
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I'm with bbnks2. Methanol will instantly drop IAT with or without an intercooler due to evaporative cooling. Of course when you are sitting in the staging lanes without methanol being injected your IAT will shoot up over 100F easily, but the moment your methanol triggers you have instantly dropping IAT.
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04-28-2017, 02:00 PM | #18 | |
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04-29-2017, 09:39 PM | #19 | |
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I'd accept a 1psi drop for a temp reduction of 50*. Edit: Additionally, boost is a measure of resistance, not flow. You might have more flow with less boost, if you lesson a restriction. Last edited by AirbusPilot; 04-29-2017 at 09:52 PM.. |
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04-29-2017, 10:57 PM | #20 | |
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04-30-2017, 07:12 AM | #21 | ||
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Based on the quote from the manufacturer, it's either a wash (less psi, but 7-10 degrees cooler) or you lose a little whp going with the 7", over the 5" stepped. If you are using a stock turbo, on your daily driver.
Once you change the profile to a larger turbo and tracking the car, the 7" becomes the answer. Quote:
Originally Posted by Tiago@VRSF View Post Our 7" unit actually has marginally more pressure drop than the OEM core. The 5" stepped offers less pressure drop than the OEM. Both designs have been proven to support anywhere from 500whp to 860whp and they're certainly more than a "hunk of metal". The 7" will out cool the 5" by 7-10 degrees on a 2-4 gear pull and it's essentially the better choice if you're interested in doing multiple gear pulls, racing or if you're planning on upgrading your stock turbos in the future. If you're looking for good IAT suppression with an easier install, the 5" stepped is the better choice.
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04-30-2017, 07:56 AM | #22 | |
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For every 10*F drop in air temp, you can subtract 600' ft from the density altitude. It'll make the engine think it's 600' lower (more dense) in air quality. Last edited by AirbusPilot; 04-30-2017 at 08:06 AM.. |
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